The present invention relates to a skew adjustment circuit, a skew adjustment method, a data synchronization circuit, and a data synchronization method.
A standard called the digital visual interface (DVI) has recently attracted attention as a standard for display interfaces. This DVI standard makes it possible to transfer image information between a host computer and a display device, not only over short distances but also over longer distances of 5 meters or more.
The DVI standard employs a protocol that is called a transition minimized differential signaling (T.M.D.S.) link, using three red, green, and blue (RGB) difference data channel and one difference clock channel. With such a T.M.D.S. link, it is necessary to provide the receiver with a function that detects and removes any skew between the data and the clock that may occur as a result of the long-distance transfer, to extract correct data. It is also necessary to provide the receiver with a function for detecting character boundaries in the received data, and a function for detecting skew between the data channels and aligning the phases of data between the channels.
The DVI standard enables a rough estimation of the algorithms and circuit configuration required for implementing these functions, but details of these algorithms and circuit configuration cannot be determined uniquely and a number of variations thereof can be considered. An example of a circuit that implements these functions was disclosed in Japanese Patent Publication No. 11-511926 (U.S. Pat. No. 5,905,769).